Shank and heel seat member for footwear



June 4, 1963 F. BAUMANN ETAL swmx AND HEEL SEAT MEMBER FOR FOOTWEARFiled July 11, 1960 2 Sheets-Shun 1 FIG 6 r. .'II.

INVENTORS r n. ML Z Z mm RH ATTORNEYS June 4, 1963 F. BAUMANN ETA].

sx-mnx AND HEEL SEAT MEMBER FOR FOOTWEAR.

Filed July 11. 1960 2 Sheets-Sheet 2 INVEII TORS Franz Baumann FranzZendron A TTORNEYS United States Patent Office 3,9l,872 Patented June 4,1963 3,091,872 SHANK AND I-EEL SEAT MEMBER FUR FOOTWEAR Franz Baumann,Niedergosgen, and Franz Zendron,

Schenenwerd, Switzerland, assignors to Ballys Shoe Factories Limited,Schouenwerd, Switzerland Filed July 11, 1960, Ser. No. 42,175 3 Claims.(Cl. 3676) This invention relates to shoes, and more particularly to ashank for shoes which is particularly adapted to use with machines forstapling uppers to shanks.

In the design of shoe soles an important consideration is that the rearportion of the sole extending from the heel to the beginning of thefore-foot must be as rigid as possible and only very slightly resilient.The rigid1ty of the rear portion of the sole is conventionally obtainedby means of card board pieces and shank members of steel or wood. Theserigid members are fitted between the usual insole and the outer sole,and the remaining empty spaces are filled with a filler. Assembling ofshoe soles having such rigid members is cumbersome and mcreases the costof production of the shoe. Moreover, unless a metal shank is used, therigidity of the sole is not always sufficient. When using steel shanksit may occur that the front end of the shank, which transmits the weightof the person wearing the shoe to the street through the outer sole,damages the outer sole. Also the weight of the shoe is considerablyincreased by such stiifening members.

In our copending application Serial No. 766,226, filed October 9, 1958,now abandoned, there is described a rigid shank and heel seat memberformed of a synthetic plastic material, such as a thermoplastic orthermosetting resinous material, which may or may not be reinforced withglass fibers impregnated in the plastic, the shank and heel seat memberbeing shaped to fit the arched shape of the shank portion of the shoeexactly so as to eliminate the use of any further stiffening members orseparate shank pieces.

Because of the necessity of making these shanks of relatively hard andrigid plastic material so that they provide the necessary support whenincorporated in a shoe, however, these particular shanks are notparticularly suitable to use in shoe manufacturing processes in whichthe uppers of the shoes are stapled to the shank during the lastingoperation. The hardness of the plastic shank, necessary to give itsufiicient rigidity, prevents the staples from properly penetrating theshank and holding the upper in place.

It is therefore an object of the present invention to provide a shankand heel seat member of a synthetic plastic material which, while it hasthe requisite hardness and rigidity to perform properly in the shoe,nevertheless can be penetrated by staples.

Other and further objects of the present invention will become apparentfrom the following specification and claims, taken together with theaccompanying drawings, in which:

FIG. 1 is a perspective view of the shank and heel seat member accordingto the present invention;

FIG. 2 is a longitudinal sectional view of an embodiment of the shankand heel seat member according to the present invention;

FIG. 3 is a sectional view taken along line 3-3 of FIG. 2;

FIG. 4 is a sectional view similar to FIG. 3 of a modified embodiment ofthe shank and heel seat member according to the present invention;

FIG. 5 is a longitudinal sectional view of a modification of the shankand heel seat member according to the present invention;

FIG. 6 is a sectional View taken along line 66 of FIG. 5;

FIG. 7 is a view of a further modified embodiment of the shank and heelseat member according to the present invention;

FIG. 8 is a longitudinal sectional view taken along line 88 of FIG. 7;

FIG. 9 is a sectional View taken along line 99 of FIG. 8;

FIG. 10 is a sectional view of a shoe with the shank according to thepresent invention incorporated therein;

FIG. ll is a sectional view taken along line 11-41 of FIG. 10; and

FIG. 12 is a sectional view taken along line 1212 of FIG. 10.

The shank and heel seat member according to the invention extends in adirection along the length of the shoe into which it is to be placed,preferably from the heel to the beginning of a flexible ball portion,the material of the shank and heel seat member having the same shape andcontour as the shape of the finished footwear in the portioncorresponding to the shank and heel portion to the beginning of theforefoot of the shoe.

FIGS. 10l2 show a sole and heel assembly for a womans shoe made with ashank and heel seat member according to this invention. The solecomprises an outer sole member 6, and insole including a flexibleforepart o1v ball portion 9 and a rigid shank and heel seat member 16extending from the end of the ball portion to the heel seat of the heel11, and a sock lining 8. The forepart or ball portion 9 of the insole ismade of any of the usual materials such as leather, cork or otherflexible material. The part 9 of the insole is attached to the rigidshank and heel seat member 10.

The upper 14 is lasted to the shank portion of the shank heel seatmember It? by shank lasting staples 15 and is lasted to the heel portionby tacks 16.

The seat face of the heel ll of the shoe is dished to provide a recess12 and the heel portion of the shank and heel seat member 1t) overliesthis recess with the edge of the upper between the shank and heel seatmember 16 and the heel ll.

Preferably, the front end of the shank and heel seat member ll; ofresinous material is attached by means of adhesive to the flexible ballportion 9. Then the composite insole is fixed to the outer sole 6 byadhesive or other conventional means and to the heel 11 by the usualscrews or heel attaching nails 17. I The general shape of the shank andheel seat member Is as shown in FIG. 1, it being curved in thelongitudinal direction to conform to the shank of the shoe, and beingdished in the transverse direction to conform to the shape of the bottomof the foot.

In the embodiment shown in FIGS. 2 and 3, the shank and heel seat membercomprises a body 20 which is comprised of a hard plastic material whichis sufficiently rigid to withstand the bending stresses imposed on themember in normal use. Embedded in the bottom surface of the body 20 is astrip of material 21 which provides an area on the bottom of the body 20into which staples from a staple driving apparatus, such as is used instapling uppers to lasts, can be driven. This strip of material 21extends substantially the entire length of the shank and heel seatmember. As seen in FIG. 3, it occupies the entire area of the bottomsurface of the body 20 Inasmuch as the staples in conventional shoemanufacturing operations are driven into only a comparatively small areaon the bottom of the shank and heel seat member, only those areas needbe such that they will receive staples. The embodiment as shown in FIG.4 has two relatively narrow strips 21 and 21 of material embedded in thebottom of body 20 along the side edges 3 thereof, the material providingtwo areas on the bottom of the body 20,, into which staples can bedriven.

The body of the embodiments of FIGS. 2-4, designated by referencenumeral 20 with :an appropriate subscript, is of a hard plastic, such asa thermosetting polyester resin, such as Polylite 8027. This resin canbe reenforced with a mat of glass fibers which are embedded in the bodyof the shank and heel seat member. The material which forms the stripsor cover, designated by reference numeral 21 with an appropriatesubscript, can be any one of a plurality of. substances. it can, forexample, be a softer plastic, such as polystyrene, or a braided glassfiber fabric or a cotton fabric impregnated with polystyrene. it canalso be a natural or manufactured fibrous material, such as leather,leather board, or fibre board such as is commonly used in the shoeindustry. The only essential limitation on the nature of the material isthat it must be softer than the hard plastic of the body 20 andsufficiently soft to take the staples.

In order to make a shank in which the body is of a hard thermosettingplastic, a fiber glass mat is placed in a mold and a liquid polyester ispoured into the mold. Then a layer of a softer plastic with a thicknessof from to V is added to the mold. This layer can also be a fibrousmaterial impregnated with a softer plastic. For example, a braided glassfiber strip may be placed in a layer of polystyrene. The entire assemblyis then pressed and molded at a tempera-aure of approximately 140 C. fora period of from /2 to 1 minute.

Alternatively, strips of soft material such as fiberboard or cottonfabric are stapled to a mat of glass fibers and the assembly is thenplaced in a mold, covered with a liquid polyester and premed and moldedat a temperature of about 140 C. for a period of about /2 to 1 minute.

In the embodiment shown in FIGS. 5 and 6, the shank and heel seat membercomprises a body 20 of a somewhat softer plastic material than theplastic material which is used in the embodiments of FIGS. 1-4, and intowhich staples can easily be driven. This softer plastic needsreinforcing strips 22 and 23 which can be of braided or woven fabric ofnatural or artificial fibers or metal. For example, there can be usedinterwoven strands of braided glass fibers. The material of the stripsis impregnated with the plastic of the body 20 which may be apolystyrene, and when the plastic hardens, the strips act as areen-forcing means for the shank and heel seat member. They provide astifiness and rigidity which is absent when the entire shank is made ofa plastic such as polystyrene. Moreover, since the plastic is somewhatsofter than the fiberglass teen-forced polyester shank and heel seatmemher, the staples are relatively easily driven into it.

The embodiment of FIGS. 7-9 is similar to'that of FIGS. 5 and 6, thematerial of the strips 22 and 23 being wire mesh or woven wire screen.As with the woven fiber material of the strips of the embodiment ofFIGS. 5 and 6, the wire screen acts as a reenforcement. As seen in FIG.9, the wire mesh strip 22 is narrower than strip 23 so that relativelywide edge areas of plastic are left exposed along the bottom of theshank body 20 to receive staples.

The molding of the shank and heel seat members of the embodiments ofFIGS. 5-9 is similar to that of the other embodiments. The woven stripon one surface is placed in the mold, the plastic poured in and then theother reenforcing strip placed on the top surface. The assembly is thencured in the manner usual for the plastic.

The shank and heel seat members: of the present invention may also beproduced by injection molding.

The embodiments of the shank and heel seat member as shown in FIGS. 5-9,while they are made of somewhat softer plastic than those of FIGS. 1-4,are nevertheless just as satisfactory from a stability standpoint. Thereenforcement strips provide the necessary rigidity which is provided bythe hardness of the plastic in the embodiments of FIGS. 1-5.

This stability is particularly important in view of the fact that ashank and heel seat member according to the present invention can besoftened in order to conform it to a particular last when it is to beincorporated into a shoe. The differences between individual lasts,which is Well known in the shoe industry, make it essential that aprovision be made for conforming the shanks to the lasts. Despite thesoftness of the shank and heel seat members of the embodiments of FIGS.5-9, however, they are extremely stable after they are rehardened, dueto the presence therein of the reenforcements.

There has thus been provided a shank and heel seat member which can beproduced in a single operation by a molding operation and out of plasticmaterial, yet which is conformable to the last for the shoe in which itis to be incorporated. It is very rigid, both before and after theconforming to the last, yet staples can be driven into it and areretained therein. The use of the shank and heel seat member according tothe present invention eliminates the necessity to use any other insoleelements, such as a metal shank, fillers, etc.

It is thought that the invention and its advantages will be understoodfrom the foregoing description and it is apparent that various changesmay be made in the form, construction and arrangement of the partswithout departing from the spirit and scope of the invention orsacrificing its material advantages, the forms hereinbefore describedand illustrated in the drawing being merely preferred embodimentsthereof.

What we claim is:

1. A shank and heel seat member for an insole for footwear, said memberconsisting essentially of a shaped substantially rigid thermoplasticportion, the thermoplastic being sufiicientlysoft to receive and retainlasting staples and tacks, said thermoplastic portion being adapted toextend along the length of the footwear from the heel to the beginningof a flexible ball member, said thermoplastic portion having the sameshape and contour as the shape of the finished footwear in the portioncorresponding to the shank and heel portion to the beginning of theforefoot, and a reenforcement extending along the central portion ofboth the top and bottom surfaces of said thermoplastic portion, saidreenforcement being strands of substantially inextensible materialembedded in said thermoplastic, a portion of said strands extending inthe axial direction of the member and the remainder of said strandsextending laterally of the member, said strands forming a screen-likemesh.

2. A shank and heel seat member as claimed in claim 1 in which thereenforcement on the bottom surface of said thermoplastic portion issubstantially less in width than the Width of said shank and heel seatmember, whereby lasting staples and tacks can be driven into thethermoplastic portion along the outside edges of the bottom thereofwithout interference from the reenforcement member extending along thebottom of the thermoplastic portion. a

3. A shank and heel seat member as claimed in claim 1 in which saidstrands in each reenforcemen-t are metal wire and are interwoven into ascreen.

'References Cited in the file of this patent UNITED STATES PATENTS1,695,996 Davis et al. Dec. 18, 1928 '1,920,670 Roosa Aug. 1, 19332,002,707 Moore May 28, 1935 2,013,168 Nickerson Sept. 3, 1935 2,129,588Nickerson Sept. 6, 1938 2,294,982 Hathaway Sept. 8, 1942 2,358,886Sullivan Sept. 26, 1944 2,371,322 Toothaker Mar. 13, 1945 2,558,317Schwartz June 26, 1951 2,644,250 Ciaio July 7, 1953 2,838,855 MaccaroneJune 17, 1958

1. A SHANK AND HEEL SEAT MEMBER FOR AN INSOLE FOR FOOTWEAR, SAID MEMBERCONSISTING ESSENTIALLY OF A SHAPED SUBSTANTIALLY RIGID THERMOPLASTICPORTION, THE THERMOPLASTIC BEING SUFFICIENTLY SOFT TO RECEIVE AND RETAINLASTING STAPLES AND TACKS, SAID THERMOPLASTIC PORTION BEING ADAPTED TOEXTEND ALONG THE LENGTH OF THE FOOTWEAR FROM THE HEEL TO THE BEGINNINGOF A FLEXIBLE BALL MEMBER, SAID THERMOPLASTIC PORTION HAVING THE SAMESHAPE AND CONTOUR AS THE SHAPE OF THE FINISHED FOOTWEAR IN THE PORTIONCORRESPONDING TO THE SHANK AND HEEL PORTION TO THE BEGINNING OF THEFOREFOOT, AND A REENFORCEMENT EXTENDING ALONG THE CENTRAL PORTION OFBOTH THE TOP AND BOTTOM SURFACES OF SAID THERMOPLASTIC PORTION, SAIDREENFORCEMENT BEING STRANDS OF SUBSTANTIALLY INEXTENSIBLE MATERIALEMBEDDED IN SAID THERMOPLASTIC, A PORTION OF SAID STRANDS EXTENDING INTHE AXIAL DIRECTION OF THE MEMBER AND THE REMAINDER OF SAID STRANDSEXTENDING LATERALLY OF THE MEMBER, SAID STRANDS FORMING A SCREEN-LIKEMESH.